A specially made portal crane gantry lifts out a 20m long T-section of the old concrete road deck in the western tube of the Dartford tunnel under the Thames. The deck, and side pieces, were previously cut by diamond saw before lifting and replacement the same night by a new redesigned precast segment. The operation from 8pm had to have everything ready so that part of London’s
M25 ring motorway traffic could run again at 6am the next day. Contractor Kvaerner Construction is undertaking the same procedure every night at present for a renovation of the entire 30-year-old concrete road through the tunnel. The £9M contract finishes early next year.
